Your real email is associated with your real name address and phone number for companies where you buy things. Companies and government sell and share their customer databases too often to assume you've been successful in opting out of all of them. If you give any website your email address you might as well have given them everything else too because they can associate it with your real id through the customer database companies that sell all that info.

If you had to give up your phone, real address, credit card or any other real info to open an email account (like with Yahoo, Live.com, etc), that is all "real life info". Only email accounts you managed to open using all fake info can be considered even quasi-anonymous (for the full monty you need to also be using a VPN to cloak your IP address).

Of course not all emails are, but a lot of them might as well be. Lots of people connect their real names and social media accounts to their email address and still give it out without thinking anything of it.

I dont register for very many sites. And if you think changing that email means they can't track you I have some bad news. They know who you are and that you're here right now and your UID here and that it connects to all the other sites you visit.